How to get keyCodes from Android mobile device keyboard?

Question

Currently, I am facing a problem on a mobile device. I have an input field where only some keys are allowed to be pressed: e.g. only the numbers 0–9. It works fantastic on a web browser. But when I open it in my Android mobile device it fails.

I have used keyup and keypress. keyup is working but I want to know which key fired the event from the mobile keyboard. How would I get that?

Answer 1

I'm using a array that has maping to all keyboard keys with keycode at given index and then on element's keydown i'm checking whether its allowed key or not, because in mobile some keyboard key will have the same code as numeric key's keycode so it will allow that keys.

So i'm using following to prevent that situation.

//keyboard maping array   
var keyboardMap = ["", "", "", "CANCEL", "", "", "HELP", "", "BACK_SPACE", "TAB", "", "", "CLEAR", "ENTER", "RETURN", "", "SHIFT", "CONTROL", "ALT", "PAUSE", "CAPS_LOCK", "KANA", "EISU", "JUNJA", "FINAL", "HANJA", "", "ESCAPE", "CONVERT", "NONCONVERT", "ACCEPT", "MODECHANGE", "SPACE", "PAGE_UP", "PAGE_DOWN", "END", "HOME", "LEFT", "UP", "RIGHT", "DOWN", "SELECT", "PRINT", "EXECUTE", "PRINTSCREEN", "INSERT", "DELETE", "", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "COLON", "SEMICOLON", "LESS_THAN", "EQUALS", "GREATER_THAN", "QUESTION_MARK", "AT", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "WIN", "", "CONTEXT_MENU", "", "SLEEP", "NUMPAD0", "NUMPAD1", "NUMPAD2", "NUMPAD3", "NUMPAD4", "NUMPAD5", "NUMPAD6", "NUMPAD7", "NUMPAD8", "NUMPAD9", "MULTIPLY", "ADD", "SEPARATOR", "SUBTRACT", "DECIMAL", "DIVIDE", "F1", "F2", "F3", "F4", "F5", "F6", "F7", "F8", "F9", "F10", "F11", "F12", "F13", "F14", "F15", "F16", "F17", "F18", "F19", "F20", "F21", "F22", "F23", "F24", "", "", "", "", "", "", "", "", "NUM_LOCK", "SCROLL_LOCK", "WIN_OEM_FJ_JISHO", "WIN_OEM_FJ_MASSHOU", "WIN_OEM_FJ_TOUROKU", "WIN_OEM_FJ_LOYA", "WIN_OEM_FJ_ROYA", "", "", "", "", "", "", "", "", "", "CIRCUMFLEX", "EXCLAMATION", "DOUBLE_QUOTE", "HASH", "DOLLAR", "PERCENT", "AMPERSAND", "UNDERSCORE", "OPEN_PAREN", "CLOSE_PAREN", "ASTERISK", "PLUS", "PIPE", "HYPHEN_MINUS", "OPEN_CURLY_BRACKET", "CLOSE_CURLY_BRACKET", "TILDE", "", "", "", "", "VOLUME_MUTE", "VOLUME_DOWN", "VOLUME_UP", "", "", "", "", "COMMA", "", "PERIOD", "SLASH", "BACK_QUOTE", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "OPEN_BRACKET", "BACK_SLASH", "CLOSE_BRACKET", "QUOTE", "", "META", "ALTGR", "", "WIN_ICO_HELP", "WIN_ICO_00", "", "WIN_ICO_CLEAR", "", "", "WIN_OEM_RESET", "WIN_OEM_JUMP", "WIN_OEM_PA1", "WIN_OEM_PA2", "WIN_OEM_PA3", "WIN_OEM_WSCTRL", "WIN_OEM_CUSEL", "WIN_OEM_ATTN", "WIN_OEM_FINISH", "WIN_OEM_COPY", "WIN_OEM_AUTO", "WIN_OEM_ENLW", "WIN_OEM_BACKTAB", "ATTN", "CRSEL", "EXSEL", "EREOF", "PLAY", "ZOOM", "", "PA1", "WIN_OEM_CLEAR", ""];
//Allowed keys as per your requirement          
var allowedKey = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "NUMPAD0", "NUMPAD1", "NUMPAD2", "NUMPAD3", "NUMPAD4", "NUMPAD5", "NUMPAD6", "NUMPAD7", "NUMPAD8", "NUMPAD9", "DELETE", "BACK_SPACE", "DECIMAL", "LEFT", "RIGHT", "TAB", "SUBTRACT", "PERIOD"];

//bind keydown to your element
element.on("keydown", function (e) {
        var key = e.charCode || e.keyCode || 0;
        var keyValue = keyboardMap[key];
        if ($.inArray(keyValue, allowedKey) !== -1){
              return true;
        }
        else{
              return  false;
        }
}

It's working for me hope so it will work for you also.